meshtastic
[Feature Request]: MQTT downlink without LoRa Tx and uplink local node only
Category
Other
Hardware
Heltec V3
Firmware Version
v2.2.17.dbac2b1
Description
My minimal setup looks like so:
graph LR
PC <-->|Serial| NodeA
<--> |LORA| NodeB
<--> |Bluetooth| Android
NodeA <--> |MQTT| mosquitto
the mosquitto log looks like so (converted to YAML for better readability):
---
# lora/2/json/home-prim/!NodeA
channel: 0
from: 145556388
id: 1057405219
payload:
air_util_tx: 0.125111117959023
battery_level: 101
channel_utilization: 0
voltage: 4.35400009155273
sender: '!NodeA'
timestamp: 1706448997
to: 4294967295
type: telemetry
Messages sent from Android to NodeB in the prim. channel, look like so:
---
# lora/2/json/home-secd/!NodeA
channel: 1
from: 3806671628
id: 1421562879
payload:
text: test-message
rssi: -60
sender: '!NodeA'
snr: 13.5
timestamp: 1706449977
to: 4294967295
type: text
1. Problem: The message sent from NodeB does not appear as beeing sent from NodeB instead from NodeA.
When I send a message in the "private" channel from NodeB to NodeA, the message appears as:
---
# lora/2/json/home-prim/!NodeA
channel: 0
from: 145556388
id: 1057405208
sender: '!NodeA'
timestamp: 1706448349
to: 3806671628
type: ""
2. Problem:
- The message type is empty
- There is no text at all
- And the source (sender) is not
NodeB
Is that as intended? Since to me it does not seem to be desirable.
Relevant log output
No response
The "sender" field is always the node connected to MQTT (gateway). You'll need to look at the "from" field, which is the unique node number of the transmitter, which you can map to a name received in NodeInfo messages, see also: https://meshtastic.org/docs/software/mqtt/#json-topic
For 2: do you have encryption enabled? I believe if you disable that you should see the type and text.
@GUVWAF do you mean encryption at all or the MQTT encryption:
since this one is off.
Though: with the prim. channel message from indeed seems to be the sender ID: 3806671628, but with the private message its the its in the to field.
Further is it possible to send messages via MQTT without forwarding all messages from the MQTT broker? Since enabling MQTT downlink does seem to do so.
Yes, I meant MQTT encryption. OK, yes indeed it doesn't actually work like this, it's a bit confusing. It only uplinks messages to MQTT that it is going to send out via LoRa. For messages on a channel, it will rebroadcast it for other nodes to receive. However, for a direct message, it only sends back an acknowledgment. This is probably the packet with empty type you're seeing (because the ACK has no JSON output yet).
Yes, enabling downlink indeed also means it rebroadcasts the packets over LoRa. Currently you can't configure that separately (except when completely disabling LoRa Tx). What you can do with firmware 2.2.19 is letting other LoRa nodes ignore messages that came via MQTT.
You made good points and I think it's worth to revisit the MQTT-related settings.
Great, I guess it'll be good to be able to set a list of topics to subscribe to / forward.
Hope you don't mind that I'm renaming and re-purposing it as a feature request (since the sender/from fields are correct) for more granular MQTT settings and uplinking DMs to the MQTT node.